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Phase diagram of a superconductor / ferromagnet bilayer

M. Lange·M. J. Van Bael·V. V. Moshchalkov
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Abstract

The magnetic field (H) - temperature (T) phase diagram of a superconductor is significantly altered when domains are present in an underlying ferromagnet with perpendicular magnetic anisotropy. When the domains have a band-like shape, the critical temperature Tc of the superconductor in zero field is strongly reduced, and the slope of the upper critical field as a function of T is increased by a factor of 2.4 due to the inhomogeneous stray fields of the domains. Field compensation effects can cause an asymmetric phase boundary with respect to H when the ferromagnet contains bubble domains. For a very inhomogeneous domain structure, Tc~H^2 for low H and Tc~H for higher fields, indicating a dimensional crossover from a one-dimensional network-like to a two-dimensional behavior in the nucleation of superconductivity.

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M. Lange, M. J. Van Bael, V. V. Moshchalkov. 2003-11-24. Phase diagram of a superconductor / ferromagnet bilayer. https://doi.org/10.1103/physrevb.68.174522

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